Digital cameras are commonly incorporated into a wide variety of devices. In this disclosure, a digital camera device refers to any device that can capture one or more digital images, including devices that can capture still images and devices that can capture sequences of images to record video. By way of example, digital camera devices may comprise stand-alone digital cameras or digital video camcorders, camera-equipped wireless communication device handsets such as mobile telephones, cellular or satellite radio telephones, camera-equipped personal digital assistants (PDAs), computer devices that include cameras such as so-called “web-cams,” or any devices with digital imaging or video capabilities.
In digital camera devices, calibration is often needed to achieve proper white balance. White balance (sometimes called color balance, gray balance or neutral balance) refers to the adjustment of relative amounts of primary colors (e.g., red, green and blue) in an image or display such that neutral colors are reproduced correctly. White balance may change the overall mixture of colors in an image. Without white balance, the display of captured images may contain undesirable tints.
With many calibration techniques for white balance, knowledge of the camera sensor response is needed so that proper estimates of illuminant conditions can be made. In this case, every camera sensor may need to be measured during the manufacturing process in order to obtain the information that is needed to later perform calibration. The need to measure camera sensor responses of every camera sensor during manufacturing, however, can add significant time and cost to the manufacturing process associated with digital camera devices, which is undesirable.